What is leukemia?

Leukemia is cancer of the blood cells - usually the white blood cells. Leukemic cells look different than normal cells and do not function properly.

What are the different types of leukemia?

There are four main types of leukemia, which can be further divided into subtypes. When classifying the type of leukemia, the first steps are to determine if the cancer is:

lymphocytic or myelogenous leukemia:
Cancer can occur in either the lymphoid or myeloid white blood cells.

When the cancer develops in the lymphocytes (lymphoid cells), it is called lymphocytic leukemia.

When the cancer develops in the granulocytes or monocytes (myeloid cells), it is called myelogenous leukemia.

acute or chronic leukemia:
Leukemia is either acute or chronic.

acute leukemia
The new or immature cancer cells, called blasts, remain very immature and cannot perform their functions. The blasts increase in number rapidly, and the disease progresses quickly.

chronic leukemia
There are some blast cells present, but they are more mature and are able to perform some of their functions. The cells grow more slowly, and the number increases less quickly, so the disease progresses gradually.

Based on these findings, the leukemia is then classified into one of the four main types of leukemias:

computed tomography scan (Also called a CT or CAT scan.) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.

magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.

ultrasound (Also called sonography.) - a diagnostic imaging technique which uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.

lymph node biopsy - a procedure performed to remove tissue or cells from the body for examination under a microscope.

spinal tap/lumbar puncture - a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes the brain and spinal cord.